1-8-nitroanthraquinone-sulfonic acid.



luo. 059.

Umrnn' STATES Patented April 12, 19046 PATENT Orrrcn.

ROBERT E. SCHMIDT, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBEN- FABRIKEN OF ELBERFELD 00., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

1-8-NITROANTHRAQUINONE-SULFONIC ACID.

SPECIFICATION forming part of Letters Pat nt 757,058, dated April 12, 1904..

Application filed January 12, 1904.

s o n NIO 'My process for producing this body consists in treating anthraquinone-alphaesulfonic acid (see United States Letters Patent No. 743,664, dated November 10, 1903) with nitric acid or with other nitrating agents. The 1-8 and the 1-5 nitroanthraquinone-sulfonic acids are thus produced simultaneously, which can be readily separated from each other owing to the different degrees of their solubility or that of their salts.

In order to carry out my invention practically, I can proceed as follows, the parts being by weight: Fifty parts of nitric acid (45% Baum) are introduced into a solution of one hundred parts of the potassium salt of anthraquinone alpha monosulfonic acid in seven hundred and fifty parts of a ninety-six per cent. sulfuric acid while stirring. The temperature rises during the operation. On further heating to to centigrade the L5- nitroanthraquinone-sulfonic acid separates in the shape of crystals. It is then stirred at this temperature for about from six to eight hours. After cooling, this acid is filtered off on asbestos from the reaction liquid, which contains the 1-8-nitroanthraquinone-sulfonic acid.

Serial N... 188.703. (N0 specimens.)

The 1-8-nitroanthraquinonesulfonic acid is obtained in the shape of crystals on either adding to the filtered solution one hundred parts of water or on introducing the filtered solution into from twelve hundred to fifteen hundred parts of water and cooling. The sulfonic acid thus produced can be converted into its sodium or potassium salt by the addition of common salt or of chlorid of potassium to its aqueous solution. The new body thus obtained represents in the shape of its potassium salt microscopic needles soluble with difiiculty in cold water. By reduction 1 am idoanthraquinone 8- sulfonic acid results. On being heated with an aqueous solution of monomethylamin it is transformed into the 1-methylamidoanthraquinone-8sulfonic acid. By further heating this body with methylamin to to centigrade sym. 1 8 dimethyldiamidoanthraquinone results.

Instead of nitrating in a mixture of sulfuric acid and nitric acid the nitration can also be performed with cone. or monohydrated nitric acid alone.

Having now described my invention and in what manner the same is to be performed, what I claim as new, and desire to secure by Letters Patent, is-

The herein-described new 1-8-nitroanthraquinone-sulfonic acid, which in the shape of the potassium salt forms microscopic needles soluble with difficulty in cold water; being transformed into 1-8-amidoanthraquinone sulfonic acid when treated with reducing agents, and being transformed into 1-methylamidoanthraquinone-8-sulfonic acid upon treatment with an aqueous solution of methylamin, substantially as described.

Intestimony whereof I have signed my name in the presence of two subscribing witnesses.

ROBERT E. SCHMIDT.

Witnesses Orro KoNIG, J. A. RIrrnRsHAUs. 

